Cameron Diaz's fem spin on Billy Bob Thornton's Bad Santa draws slutty variations on Ho Ho Ho that should have added up to raunchy fun. Sadly, it only took about 10 minutes to wipe the smile off my face. Bad Teacher keeps running away from its combustibly nasty premise. Damn shame. Diaz looks ready to shock as Elizabeth Halsey, a 7th grade educator buried in Illinois where teaching credentials are clearly way too easy to come by. On her first day, Miss Halsey props her Christian Louboutin heels on her desk, runs a DVD of Edward James Olmos teaching tough in Stand and Deliver and proceeds to sleep off whatever wasted her the night before. Prim colleague Amy Squirrel (Lucy Punch in the film's stellar comic turn) is scandalized, but gym teacher Russell Gettis (Jason Segel, charmingly lowkey) is the bee to Elizabeth's honey. Bury your stinger, buddy. Elizabeth's personal syllabus is all about finding a new sugar dude to replace the rich fiancé (Nat Faxon) who kicked her to the curb. Bachelor No. 1 is teacher Scott Delacorte (Justin Timberlake), from a wrist-watch fortune.

The problem is Scott's last love had ginormous breasts, which means Elizabeth will need a quick $10,000 for a boob job. Having that that sinking feeling yet? Thinking that misogyny's ugly head is lurking behind every frame? It gets much worse. The script by Gene Stupnitsky and Lee Eisenberg (Year One, OMFG!)) gives director Jake Kasdan (Walk Hard: The Dewey Cox Story) scraps to work with, forcing the overqualified cast to strain hard for laughs. The dry-humping scene with Diaz and former flame Timberlake falls embarrassingly flat. The students in the movie barely register, except as punching bags. And the editing has the subtle edge of a buzzsaw. How did Elizabeth even become a teacher? The movie doesn't know or care. So why should we?